Control for charging storage batteries.



P. W. SCHMIDT. CONTROL FOB CEABGING STORAGE BATTERIES. APPLICATION FILED AUG. 8, 1910.

976,750. Patented N0v.22,191o.

qu!!! r 976,750. ,l 'oi-mm1 application mea my 4, 1910,

To all whom, it may concern.' t'

Be it known that I, FREDERICK W.

FREDERICK w. scHM1D'r, or PHILADELPHIA, PENNSYLVANIA.

- vCONTROL rFOR CHARGING STORAGE :BAT'I|.EllitIlElS.-

SCHMIDT, a citizen of th'e United States, residing ,in the city and county of Philadelphia', .State of Pennsylvania, -have invented a new 4and useful Control for Charging Storage Batteries, of which the following is f a specification.

. My invention consists of an improved device for cutting out the char ing circuit in ,y charging storage batteries at t e rise of temperature in the same beyond a predetermined oint. v

p It further consists of other novel features 'ofv construction, all as will .be hereinafter full set forth. f

f T 1e annexed drawings and the following description set forth in detail, one mechani- V cal form embodying theinvention; such detail construction being "illustrative of one of various mechanical forms in which the principle of ythe' invention, 'as set forth in the concluding claims, may bel embodied.

. lFigure 1 represents a diagram of a Stor-- age battery and its charging and controlling ,.means, embodying my invention.l Fig, :2

' ytuate` a cut-out device lin the charging cirlcuit to eutk out the battery when the temperature in the *same rises beyond `a prede-- representsa perspective view of one form ofy thermostat applicable to my apparatus. Fig.

8 represents a `longitudinal section ofsuchl thermostat.

Similar numerals-of reference indicater corresponding parts in the figures.

Referring to the drawings-:-The present invention lean improvement rupon the invent-ion disclosedin my co-pending application, Serial "N o. 537,803, filed J an. 13, 1910,

for, battery "temperature controller. Said latter consists essentially in a thermostatic` deviceimme'rsediin a storage battery during chargingo the same and constructed to acterm'ined'point. f' This thermostathas a metallic, electricall -conductive but acid-resisting casing Whic usually contacts with one of the :elements lin the-battery.`

In .the presentapparatus, contact ofthel thermostat casing with an element `of the y.battery is dispensed with, and the thermostat forms aterminal of the shunt circuit ofthe `'controlling means and withinv the battery and `from the'chargin'g circuit,

The present inventionis disclosed-in-my application lfor Letters Patent, No. 559,286,

filed May 4, 1910, of which this application is a division, and I do not desire to claim in this a plication the lsubject-matter re-y maining c aimed in said application.

In the diagram, Fig. 1, the battery to be charged is indicated by the -numeral 1, having rone conductor, 2, leading through a switch, 3, from one terminal of a generato'r, 4, and another conductor, 5, connected to the other terminal of the generator. .This- Specication of Letters Patent. Patented NOV. 22, 1910.

Serial No. 559,286. vDivided and this application led- August 8, 1910, Serial No, 576,122.

comprises the charging circuit. An auto- L matle circuit breaker, *in the present instance dlsclosed as a knife-switch, 6, 1s connected 1n the circuit and closes the same when the blade of the switch engages its "terminals and is so held by a trigger which forms a part of or is connected to the armature of an electro-magnet, these parts forming a holding and vreleasing device, 7, for the circuitbreaker. The electro-magnet is wound in a branch for shunt circuit, one terminal,8, of which is connected to the char ing circuit throu h the circuit breaker, whi e its other termina 9, is connected to one contact member of the thermostat 10, which is immersed in the battery solution, when the device is in operation. All of these elements and connections are substantially the same as those disclosed in my above referred to application, and need not be specifically described.' l

The thermostat has a casing, 11, of 'lead or other electrically-conductive and acid- 'resisting metal, and a plate, 12, is secured tb the bottom lofl this casing andy in electric contact lwith the same. A composite strip,

13, such las usually employed in thermostats, is secured to this plate and will contact,

when flexed by rise o'f temperature, with .al

lcontact-screw, 14, in an arm, 15secured upon but insulatedfrom a screw-post, 16,

upon the base plate 12. The contact-screwl "is connected by a wire, 17, 'to a screw, 18,

whichv is insulated from the 'cover of the..

casing by means of an insulating washer,l19, and projects outward through an opening in the cover. The enlarged ',jbase, 20,y of Va screw-post, 21,"of lead or similar acid-resisting'metal issecured 'upon the screw, 'and is insulated from the cover by an insulating 111.05`

filling, 422, also closing the opening in the cover.

ofA the branch or shunt Y'circuit can' "be in-l serted and secured by a nut, 24preferab1y11 The `screw-,post l21nl'1as a transverse hole, 23,"through` which ythe wire terminal of hard rubber or otheracidfresisting and non-conducting material. The casing is tightly closed by its cover which is soldered or fused on, and its interior is completely filled with a heat-conducting but insulating liquid, such as transformer oil or similar oil, which will ymaintain insulation of the parts within the casing, conduct heat from the walls of the casing to the thermostat strip, and prevent the formation of an arc between the contact points and thus preserve the same from burning or fusing. The casing fits within an apertured insulating jacket, 25, of hard rubber or other insulatmg material, which will prevent metallic contact of the casing with the battery elements and at the same time give free conductive access for the solution to the surface of the casing. The apertures Q6 :of the jacket will permit the solution to act against all sides of the casing to convey a part of the battery-current to the same, but the jacketv will prevent direct metallic contact of the casing with the elements of the battery and thus prevent short-circuiting `by accidental contact of the casing with two elements.

When charging a battery, the terminals of thev charging circuit, which has been closed at the ymain switch 3 and circuit-breaker, are connected to the binding .posts or similar terminals of the battery, and the current from the generator will thus charge the battery. The thermostat, which is connected to one terminal of the shunt circuit, is placed in the battery, immersed in the solution. If, during the charging of the battery, the temperature in the latter rises above a predetermined degree,usually about 105 Fahrenheit,-to which the thermostat has been adjusted to close contact, the contacts close the shuntcircuit through the same, as the casing of the thermostat forms a terminal in the battery and thus diverts a portion of the circuit flowing through the battery, to the shunt circuit. This will energize the electro-magnet in the shuntcircuit and cause the latter to attract its armature and release the circuit-breaker, which will thus cut out the battery from the charging circuit and prevent damage from overheating and overcharging. All of' this operation 1s substantially like in the device o my first application, No. 537,803,iabove 'referred to,`excepting in so far as the ther-i mostat casing, or as much thereof as is metallic, is therein disclosed as in contact with a battery'element, while in the present device, the shunt circuit derives its connection in the battery circuit by the thermostat casing forming a terminal of the shunt circuit in the battery without direct con-t tact, in fact, being insulated from such` contact by its jacket, but deriving its current when the contact of the thermostat is closed through the battery solution which carries f i the current.

As the charging of the storage batteries ofv electric vehicles 1s usually in the hands of nished by inclosing the casinggin its in.

sulated jacket, and making the thermostat casing a terminal of the shunt circuit in the battery, active only when the contacts Within it close by rise of temperature. At other times, of course, the casing is inert.

While for the present purpose it is more so j.

desirable to retain the insulating jacket, this latter feature does not form an essential part of the present invention, being the subject-y matter of the claims in my application, No. 559,286, but such jacketis a desirable adjunct to the apparatus.

While the thermostat is disclosedas located between the elements of the battery but out of electrical contact with the same, it is evident that the insulated thermostat may be placed anywhere in the battery, as, for instance, upon two elements and straddling the space between them, so long as the thermostat is immersed in the battery solution to connect with the current through the same and to thus form a terminal of the shunt-circuit.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:-

-1. In a device of the character stated, a charging circuit, a storage battery in said circuit, an automatically opening circuitcuit, an electro-magnetic retaining and releasin woun in the shunt-circuit, and a thermostat immersed in the battery solution and inclosed in an acid-resisting metallic casing and having one contact connected to the shunt circuit and the other 'contact connected to the casin ,-said casing thus form-v in g a terminal o the shunt-circuit in the battery.

2. In a device of the character stated, a charging circuit, a storage battery in said circuit, an automatically-opening circuitbreaker inthe circuit, a shunt-circuit having one terminal connected to the charging circuit, an electromagnetic retaining and releasin device `for the circuit-breaker and woun j in the shunt circuit, and a thermostat immersed in the battery solution andhaving an electrically-conductive and acid-resisting casing electrically connected to one of its contacts'and the other contact connected to the other lterminal of the shunt circuit,-

device for the circuit-breaker and said thermostat thus forming a terminal of the shunt-circuit in the battery.

3. In a device of the character stated, a charging circuit, a storage battery in the same, an .automatically opening circuitbreaker having electro-magnetic controlling means, a shunt-circuit having one terminal connected tothe charging circuit and connected to actuate said cont-rollingmeans, and an incased thermostat immersed in the battery solution and having one contact connected to a terminal having electrical con- `tact with the battery solution and one contact connected to the other terminal of the shunt circuitl 4:. In adevice of the character stated, a charging circuit, a storage battery in such circuit, means in said circuit for cutting out the battery, and a thermostat having an electrically-conducting and acid-resisting casingland Wholly Within the storage battery and conneetedtto control said cutting out means. Y

5. In a device of the character stated, a

charging circuit, a ystorage battery in suchV exposed to the same and having one contact connected to such element and the other contact connected to the other terminal of the branch circuit, and an electro-magnetic releasing device for the circuit-breaker and Wound in the branch circuit.'

FREDERICK W. SCHMIDT.

'Witnessesz WM. CANER WIEDERSEIM, J. C. MCGLASHEN. 

